Salt weathering impact on Nero/Ramses II Temple at El-Ashmonein archaeological site (Hermopolis Magna), Egypt

AbstractNero’s Temple at El-Ashmonein archaeological site, in Minia (middle of Egypt), is considered one of the most important of all temples of Nero. This temple dates back to 1520 BC–1075 BC in the New Kingdom and was reused in the era of Nero (the Fifth Emperor of Rome). The temple construction materials are severely decayed from surrounding environmental impacts, especially contaminated water sources. The main objective of this paper is to identify the construction materials of Nero’s Temple and their decay by-products. To achieve them, X-ray diffraction, micro X-ray fluorescence spectrometry, and portable Raman spectroscopy were utilized to identify the compositions and alteration by-products/degradation compounds (mainly saline efflorescence and crusts) from the construction materials, such as limestone walls, and structural mortars of the temple. In addition, a polarizing microscope was used to identify the minerals inside the construction materials and reveal the alteration of the minerals because of decay. Digital microscopy and scanning electron microscopy with EDS were used to detect decayed materials' morphological features. Finally, results showed that the main decay factor is salt attack (chlorides, sulfates, phosphates, nitrates, carbonates, and bicarbonates) for all architectural and structural elements of the temple, which have been carried to the construction materials from various sources of contaminated water (canal, sewage, and agricultural water). Graphical Abstract